1. Field of the Invention
The present invention pertains to thermal barriers and pressure seals. Specifically, it pertains to apparatus suitable for providing both pressure sealing and thermal isolation. Still more specifically, the present invention pertains to a combination thermal barrier and pressure seal suitable for use in spacecraft.
2. Brief Description of the Prior Art
In conventional aircraft there are several movable control surfaces, such as ailerons, elevators, rudders, trim tabs and the like. To prevent undue turbulence, reduction in control and fuel efficiency, it is desirable to provide proper pressure sealing at the junctions between such control surfaces and the adjacent structure of the aircraft. Examples of such sealing apparatus may be seen in U.S. Pat. Nos. 2,368,702 and 2,381,350.
Some aircraft are provided with adjustable wings which at least partially retract into the fuselage under certain conditions of flight. Sealing of the fuselage recess is necessary to prevent undesirable aerodynamic effects, particularly in high-speed aircraft. Various flexible and sometimes partially inflatable seals have been developed for this purpose. Examples may be seen in U.S. Pat. Nos. 3,480,237; 3,797,784; 3,987,985; and 4,029,272.
In designing spacecraft for flights to outerspace, it is, of course, necessary to provide proper pressure sealing at the junction between control surfaces and the adjoining spacecraft structure to prevent harmful aerodynamic effects. In addition, consideration must be given to the extremely high temperatures encountered in space flight where temperatures in excess of 1,000.degree. C. are not uncommon. While the surface of the spacecraft may be protected against extreme temperatures, it is not as easy to provide temperature protection for the recessed areas normally associated with the various aerodynamic control elements of the spacecraft. Some of these areas require both pressure and thermal sealing and if a sealing assembly could be designed to satisfy both requirements, it would be highly desirable. However, prior to the present invention, such a combination pressure and thermal seal suitable for such sealing in a variable space has not been found.